Global Warming: Past the point of no return

[KASASpace]

Hmm, interesting to note, if we simply stopped using so many Greenhouse gases, than eventually the Earth would settle down.

You see, Humans evolved during the time where the Earth had the most climate change (I'm not saying Global Warming isn't true or anything)

But, I have to say, there is more than just ONE greenhouse gas......

[Red Iron Crown]

That's horrific, EUTHANASIA? FREAKING GENOCIDE? That is sick. Who decides who lives and who dies? Who is given such a god like power?

Offer $1,000,000 per volunteer, payable to the person's estate/inheritors. I think you might be surprised how many volunteers would take that offer. Not genocide, no involuntary deaths.

Note: I'm playing devil's advocate here, I would hate for things to reach a point where such measures were necessary.

[architeuthis]

Imagine building mirrors with areas of hundreds of kilometers, without hitting satellites or micrometeorites, Drag would be intolerable, etc

Why ever would you put in in LEO? They would have to be enormous there. Build them at the Earth-Sun L1 point. No drag to contend with either. Wouldn't be cheap, but it is essentially doable with our current level of technology.

Even if we were to abandon all forms of power generation, population growth would STILL come back to bite us in the arse eventually.

The established long term trend since the 70's has been declining world average rates of population growth. Birthrates have fallen around most of the world due to increases in education, increased standards of living and longevity, and improving access to healthcare. Human populations are growing, but by lower and lower rates each year. The U.N. projects a worse case scenario of the world population peaking in the 2050's at around 10 billion people, and declining gradually afterwards as the world average growth rate becomes negative (as it already is in most of the developed world). Other estimates suggest the peak will come sooner at 8-9 billion. The current world population is over 7.2 billion. The Malthusian problem has been avoided for decades because of huge improvements in agricultural productivity. This trend doesn't seem to be changing, though water resources will likely grow more scarce in the relatively near future. In the historical context war, disease and pestilence seem to be at record lows as well. So much for the horsemen.

Fossil fuels, and biodiversity loss are the big problem for humanity right now. Part of the solution seems pretty straightforward: switch to renewables and nuclear. Land use habits may be more difficult to change.... Also, we might still need the sunshade to deal with the damage already done. But no death camps are necessary. Seriously, it depresses me to hear this typically anarcho-primitivist type fire and brimstone (unfortunately not uncommon among some of my fellow environmentalists). It reminds me of the people who pray for the apocalypse and they day when they can be raptured up to heaven and watch the unrighteous burn on Earth.

Edited April 14, 2014 by architeuthis

[NERVAfan]

IIRC it's just barely possible for the Earth to be pushed into an unsurvivable 'runaway greenhouse' state given its insolation. I doubt there is enough fossil fuel in the world to get us there.

I can see us ending up in an Eocene/warmer parts of the Mesozoic type scenario with no permanent ice cover - 'hothouse earth' - but that is survivable. Ecologically disastrous, yes, and tragic on a human level too -- agricultural regions would shift enormously, sea levels would rise and flood coastal cities*, much of the human population would have to move, especially bad in the poorer nations which have less spare resources to relocate people and feed them. We should make huge efforts to avoid it -- but the planet won't actually cook or turn into Venus. EDIT: Humanity will survive, civilization will survive.

*I can't see seawalls working if the East Antarctic ice cap melts with its ~60 meters of sea level rise, but that would take ages given its gigantic thermal inertia.

If it somehow did happen, we'd have to remove CO2 from the atmosphere with 'carbon capture and storage' technologies, use things like iron fertilization of the oceans to try to trap more CO2 biologically, and even try the crazier things like injecting sulfur dioxide into the upper atmosphere to darken the skies and cool the planet (this is mostly why huge volcanoes like Krakatoa and Tambora cool the world, the ash mostly falls out quicker, it's sulfur aerosols in clouds that do most of it). Of course that has the side effects of acid rain and more, but if the world was going to cook...

Even if we were to abandon all forms of power generation, population growth would STILL come back to bite us in the arse eventually.

If you want to see where overpopulation combined with energy consumption will lead, we've got a convenient preview of it in Beijing.

And I saw it estimated somewhere, that even if we were able to magically turn on a global utopia switch tomorrow, we already couldn't grow enough food to feed everyone. There's not enough arable land.

This is not true.

The ONLY reason our current agriculture is at all 'unsustainable' is because of its use of fossil fuels; if we switched to renewable energy we'd be entirely OK food-wise. The US farm subsidies etc. actually mean we farm very inefficiently. I would be surprised if current technology couldn't grow enough food for 20 billion people (note that China is a net exporter of food, is the same land area as the US, and is probably worse farmland on average -- I would expect US at max efficiency to be able to feed several billion people minimum).

And technology will continue to improve. The Sahara desert was mostly grassland until ~7000 years ago, we could probably change it back (probably even without too many ecological ramifications; 7000 years isn't much time for evolution, the species should be able to survive in a wetter environment). And we are just entering the age of genetic engineering; I don't think crops 10x as efficient in calories/acre/year are at all unlikely in 50-100 years... possibly much sooner if we stop being paranoid about GMO crops.

(As for that, even corn is completely un-natural; most people wouldn't recognize the wild ancestor, teosinte, as being corn -- it looks more like some ugly wheat/weed hybrid. And there is all kinds of crazy hybridization and genome-switching in nature, there's a grass in North America that has octets of chromosomes instead of pairs -- octets composed of 4 separate pairs, from 4 separate ancestral species -- it's a four-way hybrid. Bacteria swap plasmids all the time.

And even "transgenic" organisms, DNA transfer between wildly distantly related organisms, exist in nature. A sea slug, Elysia chlorotica, has incorporated DNA from the algae it eats into itself. The bacterium, Agrobacterium tumefaciens, used in genetic engineering naturally inserts its DNA into plants. )

--

Overpopulation is pretty much a myth; Malthus was simply wrong - a technological society's ability to feed itself will grow faster than population.

Especially since birthrates are crashing in the developed world; below replacement in most developed nations. We will actually have economic problems as a smaller working-age group has to support a huge retired group.

Edited April 14, 2014 by NERVAfan
asterisk

[Nuke]

That's horrific, EUTHANASIA? FREAKING GENOCIDE? That is sick. Who decides who lives and who dies? Who is given such a god like power?

when it comes right down to it, humans are horrific creatures. in the decay of civilization this will inevitably cause, those with the power to do so will horde and ration out resources, let people live, and dispense murder whenever it suits them. forget about suicide booths, there will be cannibalism.

Edited April 14, 2014 by Nuke

[Rakaydos]

My understanding is that "runaway greenhouse" implies temperatures and conditions that provoke spontanious geoloical emmission of more greenhouse gasse and effects, and that it becomes a self sustaining rection, like dropping a match on one side of a oil spill.

[Seret]

The established long term trend since the 70's has been declining world average rates of population growth.

True, but there is a major caveat here. Countries only go through the demographic transition to lower birth rates when they industrialise, standards of living go up and child mortality and social security rise to levels where they can risk having fewer children. The problem is that when they do this, energy use rises. So essentially the problem is that we either let the developing world match our levels of wealth and see energy use use rise, or we watch them wallow in povety, population continues to grow and energy use rises. Hence our energy problem. Personally I'd definitely go for the first option, it's more humane and at least the population problem stabilises so we can plan effectively.

However, the OP's question wasn't about our prospects of tackling the energy problem, they were suggesting we'd already lost that battle and the climate had dived into a positive feedback loop. I'm not confident there's much we could do. We lack competence at controlled geoengineering, so we'd be making it up as we went along, and the consequences of any mistakes would be dire, so we'd need to be fairly cautious. Ideas such as spraying aerosols into the atmosphere to increase radiative forcing have been mooted, as has seeding the oceans (with iron, IIRC) to increase their ability to sequester carbon. Manual geological sequestration of emissions is still an experimental technology, and unlikely to be effective on the scale we require IMO.

As for giant sunshades, it might not be necessary to build them from scratch, and they would need to cover more than a fairly small fraction of the incoming sunlight. Cheapest option could be grabbing asteroids and moving them to a lower orbit, and the technology to do so is available now. Why haul all that mass up from Earth when there's plenty of big lumpy rocks lying around up there?

The main problem of course is that projects on this kind of scale would require massive international cooperation, and that's difficult to pull off at the best of times. During an existential crisis it's not at all certain that we'd be able to get everybody to agree on any one course of action. It's likely that you'd get a small group of wealthy countries having to simply do what they thought best, and hopefully most of the others wouldn't be doing too much that actively worked against what they were doing.

There are a lot of little simple things that we should be doing already though. Painting every roof in the world white would have a relatively moderate effect, but is extremely cost effective and low tech enough to be achievable.

Edited April 14, 2014 by Seret

[magnemoe]

My understanding is that "runaway greenhouse" implies temperatures and conditions that provoke spontanious geoloical emmission of more greenhouse gasse and effects, and that it becomes a self sustaining rection, like dropping a match on one side of a oil spill.

Yes, this happened on Venus, water vapor is also an major greenhouse gas, this was probably the trigger on Venus, water vapor increased temperature making more until the seas boiled off, this stops carbon being bound to minerals and start baking it out.

its very unlikely it can happen on earth, at least higher temperatures will not do it, tempratures during the time of the dinosaurs was far higher then now.

During the early life Earth had some wild swings, probably because oxygen reacted with everything, in short earth almost frose over with ice reaching equator, then volcanoes released co2 who was able to increase heat even if the ice reflected almost all light, as it was ice everywhere nothing was able to absorb co2, then the ice melted the temperature skyrocketed and this lasted until the co2 was absorbed.

It was another smaller peak 250 million years ago as an mass extinction killed off most life.

So Earth is not Venus, not only is Venus closer to sun but it also look like unlike earth plate tectonic it get a lots of major supervolcanoes every 200 million years. Not Yellowstone class but more like Siberian traps and many of them at once.

[bsalis]

Launch giant sunshades into space between the Sun and Earth. Pump particulates high into the atmosphere. Use ships to spray ocean water into the air to increase cloud formation.

Looks like someone already posted my two suggestions.

Anyhows - if anyone is interested, theres a name for man-made solutions to these things: Geoengineering. Can Google for more material.

[Idobox]

It's very unlikely global warming could ;ake the Earth uninhabitable. The real problem is that chaning weather patterns would massively screw our food supply.

The first measure would be to seriously reduce meat consumption, for example with bans or rations. Raising animals basically turns a lot of grain into a little bit of meat, very innefficient.

The second step would be carbon capture on massive scales. Turn biomass into coal and bury it. That would be extremely expensive, but that's the only way to seriously reduce CO2 levels in human times.

Third, reduce the population. First of all killing a lot of people is a genocide only if you target specific ethnies or groups. Second, it would be terribly innefficient and brutal. Give strong incentives for people not to have children (for example give money or food to women over 16 without children), or simply move people to cities, where the natality rate always drops.

Fourth, bulldoze the suburbs and move people to high density cities. Much much more energy efficient, less transportation, less wasted heating, easier logistics, more farmland.

But we first have to stop burning fossil fuels.

[Comrade Jenkens]

- Euthanasia of a large portion of humanity to lower population to sustainable levels

As per usual the KSP community never ceases to terrify me...

[Dodgey]

The title reminded me of this.

https://www.youtube.com/watch?v=h7IZNfGEcFk

[Rondon]

and then destroy the majority of cities (only small towns left, cities were a REALLY bad idea).

Perhaps even return to hunter-gatherer situations, where it took 2000 calories to gain 2000 calories, and thus no "mass-produced" industrial fake food.

No reductions in population (there is still plenty of room for now...... in places like the North American Great Plains and if we terraformed Siberia [somehow..?])

And I would also recommend the construction of O'Neil Cylinders.

why were cities a bad idea, suburbs sure, but compared to rural life, in nearly every country city dwellers not only earn way more than there rural counterparts they also emit nearly half as much pollution, and how do you expect to construct giant habitats and terraform giant sections of earth if people spend more than half there time hunting for food?!

[78stonewobble]

As per usual the KSP community never ceases to terrify me...

Well, if we literally are in a situation, where the alternative to... well mass murder... is that all of mankind dies, but also any chance of life on earth (sofar the only place we know there is life)...

I'd have to say it's the only place I'd be ok with it. Because the alternative action or inaction causes more deaths (all) rather than the action of mass murder saves "some" lives. It is morally acceptable to kill, to save lives. Ie. for a cop to kill someone that is a danger to others (even if it's just 1 other person, which numerically comes out the same, but we'd rather have a cop living than a guy thats a danger to cops). In principle the amount shouldn't matter.

Realistically and for questions of morality, I'd rather spend the ressources making sure that some lives are saved on mars or in a space habitat though.

[78stonewobble]

I'm not convinced renewable energy is a solution.

If I remember correctly... (big if) here in Denmark, we have enough (have had for quite a few years actually) windpower capacity to generate about 60 percent of the countries electrical power. However, since we need to have our coalpower plants running to cover demand on less windy days and so on, we can actually only use 30 percent wind generated electrical power.

PS: I just checked for today... It's quite windy here so we're generating quite a lot of windpower today. Sounds great, but we still can't turn off the coalpower plants. So we have to export this energy.

If we had to cover all our, not only electrical power, but also heating power, from ie. wind and solar power It would be an incredibly massive project.

Building something massive "pollutes", in the sense that it adds to global heating. It pollutes to take ressources out of the ground. It pollutes to turn those ressources into turbine and blade and solar power panels. It pollutes to transport them around. It pollutes to replace co2 absorbing plants with massive areas of powerplants.

Denmark, a small country with only 5 mio. people, would probably need 148 squre kilometers of solar powerplant to cover the electrical needs or 2000 windmills or a combination there of. In addition to that comes the added poweruse for heating.

[Dodgey]

You are forgetting fission power, while not renewable it is orders of magnitude better than fossil fuels, and that's without mentioning fusion.

[Seret]

I'm not convinced renewable energy is a solution.

It's part of the solution, but no one technology is THE solution. A good grid should have a mix of power sources anyway. Renewables can be intermittant like wind and solar, or very predictable like tidal. Large hydro can even store power from other renewables that are generating at the wrong time.

If we had to cover all our, not only electrical power, but also heating power, from ie. wind and solar power It would be an incredibly massive project.

Indeed, heat a massive problem. As is transport. People get all excited about electricity, but unless you see us moving to an all-electric system soon then it's only part of the picture.

However, the topic of this thread isn't really about what energy systems we need to avoid runaway climate change, it's about what we'd do if we hadn't managed to avoid it. Reducing CO₂ emissions at that point wouldn't actually address the problem.

[Comrade Jenkens]

Well, if we literally are in a situation, where the alternative to... well mass murder... is that all of mankind dies, but also any chance of life on earth (sofar the only place we know there is life)...

I'd have to say it's the only place I'd be ok with it. Because the alternative action or inaction causes more deaths (all) rather than the action of mass murder saves "some" lives. It is morally acceptable to kill, to save lives. Ie. for a cop to kill someone that is a danger to others (even if it's just 1 other person, which numerically comes out the same, but we'd rather have a cop living than a guy thats a danger to cops). In principle the amount shouldn't matter.

Realistically and for questions of morality, I'd rather spend the ressources making sure that some lives are saved on mars or in a space habitat though.

A much more viable alternative would be a worldwide effort to quickly build mass renewable power generators over massive areas of the surface to cut carbon emissions. Also mandatory switching to electric cars and construction of millions of scrubbing towers to absorb the CO2. Also replace cattle farming with grain production which takes much less energy for the same amount of food while eliminating one of the largest sources of greenhouse gasses.

It would be a worldwide effort and not particarly nice but it sure would be better than the mass murder of billions. Once the situation had stabilised again money could start being put into developing a future hydrogen economy which could raise the quality of life but retain the ability to be environmentally friendly.

[Klingon Admiral]

Well, if we literally are in a situation, where the alternative to... well mass murder... is that all of mankind dies, but also any chance of life on earth (sofar the only place we know there is life)...

Nature laughs about the current climate change, it has been through much worse. The earth has already been much hotter than it would be even after the most severe predictions.

[Guest]

It's not really about nature. It'll adapt. Species will be dying out, but in their place, new ones will emerge. Nature has been through worse. Evolution and natural selection will sort them out. We should not be putting "nature" over the Human civilization. However, in that case, we are also threatened. Netherlands would be pretty screwed if the sea level rises, as would some other low and coastal areas.

My answer is simple: go nuclear, then fusion once it's viable. All the anti-nuclear activists are idiots who know nothing about the workings of nuclear reactors. Compared to wind (bird killers), water (fish killers, massive landscape changes), solar (needs too much area and is too inefficient) and geothermal power (only viable in a few places), nuclear is more powerful, cleaner and much cheaper in long run. No renewable energy source can compare.

[Seret]

My answer is simple: go nuclear, then fusion once it's viable.

No one energy source provides all the answers, nuclear has big problems too. It's expensive and we still have no solution for high level wastes. Also, large thermal plants such as nuclear aren't good at demand following. It'll form part of the solution (typically as base load) but it isn't a complete solution on its own.

Also (and people seem to be missing the point a bit here) no type of fuel switching will help if we've passed the point where the warming is caused by human emissions, which is the OPs whole premise.

[Comrade Jenkens]

Also (and people seem to be missing the point a bit here) no type of fuel switching will help if we've passed the point where the warming is caused by human emissions, which is the OPs whole premise.

As I said: Build millions of scrubber towers to start cleaning the atmosphere.

[Seret]

As I said: Build millions of scrubber towers to start cleaning the atmosphere.

Ok, which scrubbing technology would you go for? How are you going to manage the wastes and the energy requirements? What are you going to do with all the CO₂? What would you do about other greenhouse gases like water vapour and methane?

[Dodgey]

While I do agree that the science behiend the scrubbing towers needs to be explained, a pessimistic attitude is not helping the conversation in anyway.

[Comrade Jenkens]

Ok, which scrubbing technology would you go for? How are you going to manage the wastes and the energy requirements? What are you going to do with all the CO₂? What would you do about other greenhouse gases like water vapour and methane?

I explained in my post before that. Massive increases in renewable resources and nuclear power to make up for the energy demand of the towers. Stop using cattle as a food source.

As for the CO2 extracted, simply do anything to stop it returning to the atmosphere. I'm pretty sure my suggestion is more reasonable to exterminating most of the human race.